How To Replace A Fender

Most Read

Pickup truck owners have lots of friends. My pickup is regularly borrowed to move everything from cordwood and college kids to upright pianos and snowblowers. When it was new I always rode shotgun to make sure my truck didn't get banged up, but that grew old once I realized I would always be the mover's helper.

Then a friend accidentally ran the right-front corner into a low post--doing just enough damage to the fender to exceed his ability to pay for it, but not enough damage to exceed my deductible.

Fortunately, only the fender was smacked, so I reasoned I could buy a new one and easily bolt it on myself. Modern basecoat/clearcoat paints make a professional refinishing job very easy with nothing more than an air compressor and spray gun, as long as you're willing to color-sand and buff out the finish once it's dry.

Even paint matching--once the bane of all would-be auto painters--is simple, thanks to the modern paint-matching equipment that many well-equipped auto stores have. Basecoat/clearcoat paints are extremely forgiving to apply. To choose the proper paint color, find the paint code, which is usually located on a doorjamb or the trunklid. If you can't find the code, take a piece of the car, like the gas cap, that has the original paint to the paint store and have them match it with their machine.

There used to be two choices for finding a replacement fender: Buy one from a dealer or find a good used one at a wrecking yard. Today, there are many more options.

Just as you can buy more than one kind of aftermarket shock absorber or battery for your vehicle, you can buy an aftermarket fender that costs less than the factory fender. This is especially true for vehicles that have the same body style over many years.

Once you get the new fender home, it's a good time to paint its hidden surfaces with something more rust-resistant than the primer applied at the stamping plant. Rattle-can enamel is fine as long as you clean and lightly sand the primer first. The last step before spraying any paint is to carefully degrease the surface with prep solvent.

OFF AGAIN, ON AGAIN

The procedures for removing a fender vary widely. This task can be easy or hard depending on the vehicle. When removing any fender, take a moment to note where fasteners are, and what items you might need to take off first, such as the bumper, antenna, grille or headlight bucket. On some vehicles the hood hinge is bolted to the inside of the fender. If that's the case, you'll need to prop the hood open before removing the fastener there. Removing the hood entirely may make it less prone to damage during the repair procedure. If so, mark the position where the hinges attach to the hood with a scribe or felt pen to make it easy to realign later.

You'll also need to remove any cladding, marker lights or trimpieces from the fender. You probably will want to reuse them--so take care. Trimpieces in general can be tough to remove, as they are held on with very aggressive double-sided tape. Goof-Off, 3M Trim Adhesive remover or even lacquer thinner will soften the adhesive so you can remove the trim without bending it.

Painting isn't as daunting as it used to be. Modern basecoat/clearcoat paints are easily sprayed using simple home shop equipment.

You may also need to take a utility knife and slice any seam sealer or undercoating that makes the fender adhere to the body. When lifting off the fender, take care not to scratch the door or hood.

To repair minor rust damage around bolt holes, or where the fender contacts the body, wire-brush the area clean. Then coat it with a chemical rust converter, available at auto parts stores. Once the converter is dry, paint the area with a zinc-rich primer from an aerosol spray can. Even if there's no damage to repair, take a few minutes to wire-brush the area where the fender contacts the body. Any imperfection, dirt or leftover seam sealer will prevent intimate contact between the new parts and the old--which may prevent the new part from fitting properly.

Install the fender by positioning it on the vehicle and holding it in place with several bolts that are loosely fastened. Most fender fasteners and their mounting points allow a certain amount of movement when loose to allow the fender to be adjusted for fit. Install all fasteners fingertight, then move the fender left and right and fore and aft to achieve an even gap at the door and hood seams while ensuring that the fender is flush with the body. After tightening all fasteners, double-check the fit and make sure the door and hood open and close properly. Leave any parts off the fender that will interfere with painting.

FENDER FINISHING

Both aftermarket and OEM fenders come coated with a durable primer sealer that's ready to accept paint. Before painting, mask off the hood, the door adjacent to the fender, and the wheel and tire immediately below the new fender. To prevent overspray, cover the entire car with plastic sheeting.

Before painting, remove any fingerprints, oil, dirt and grease with a solvent-based wax remover. The primer already applied to the fender probably has some imperfections from being handled. You'll need to sand these out and prime again, then sand lightly over the touched-up areas. Apply the basecoat according to the maker's instructions. Before spraying, gently wipe the area to be painted with a tack rag, then spray the fender. Basecoats generally dry in less than a half-hour. You may need to apply two or three coats to get adequate coverage, depending on the color. Most paint manufacturers strongly recommend not sanding between coats. Follow their recommendations explicitly, especially the parts about wearing a respirator.

Once the basecoat is dry, mix the clearcoat with hardener according to the maker's instructions, then apply a medium wet coat and let it flash dry before applying a second coat. After allowing the clearcoat to dry for an hour or two, remove all paper, plastic and masking tape from the vehicle.

After the clearcoat has dried for a couple of days, it's time to remove dust particles and any orange peel or other imperfections through a process called color sanding, followed by machine polishing. Begin by sanding the fender with 1500-grit sandpaper, making sure to keep the area flooded with water while sanding to wash away residue. Avoid sanding through the paint by staying away from creases and seams. To ensure that you sand all areas, work methodically in small sections until the entire fender has been sanded. After drying the fender thoroughly, look for any area that's shiny, as this indicates that more sanding is needed.

With sanding complete, use a foam polishing pad on a rotary buffing machine along with rubbing compound to bring out the luster of the paint. Again, stay away from creases and seams to avoid rubbing through the paint. You can increase the luster and remove swirls by changing to a fresh foam pad with another application of polishing compound, followed by another pad change, followed by the use of speed glaze. Once buffing is completed, install any parts to finish the job, then wait a month before waxing.

For this project, we ended up buying two CAPA-certified aftermarket fenders. CAPA stands for Certified Automotive Parts Association, an independent group that guarantees the fit and finish standards of a manufacturer before its parts can wear a numbered CAPA sticker.

The first CAPA fender we ordered off the Internet. But when we tried to bolt it on, it took a lot of bending, twisting and a few choice words to get it bolted up. Once it was finally in place, it just didn't fit right. Thankful that we hadn't painted the fender before installing it, we ordered a second CAPA fender (from a different maker) locally and it fit perfectly and finished beautifully.

CAPA has a program to retrieve and replace parts from unsatisfied customers. (Get the CAPA number from the sticker, then call 800-505-CAPA to file a complaint.) A much quicker route is to buy the part from a reputable local parts store. That way if the part doesn't fit, you can take it back and order another one.